Communication device with dynamic delay compensation and method for communicating voice over a packet-switched network

ABSTRACT

A device and method for communication of speech packets over a packet-switched network allows for a greater channel reallocation delay. Initial speech packets may be buffered during a channel reallocation delay and sent through an access medium when a channel is granted. A media access controller may transmit the buffered speech packets through the access medium at a rate exceeding a speech encoding rate. At the receiving user equipment, the initial speech packets are decoded and buffered. Speech signals representative of the initial speech packets may have a shortened time period to compensate at least in part for the channel reallocation delay. Decoded speech packets may be processed using a rate matching process at a rate which initially exceeds the speech encoding rate which may be gradually decreased to approximately the speech encoding rate. The rate matching may include dynamic time warping to substantially preserve attributes of the original speech.

FIELD OF THE INVENTION

The present invention pertains to the communication of voice over apacket-switched network.

BACKGROUND OF THE INVENTION

As an alternative to traditional circuit-switched networks, voicecommunications, for example, may be routed over packet-switched networkslike the Internet. Due to the fact that the Internet is not subject tothe same international regulations as are traditional telephonenetworks, routing voice communications over the Internet tends to beless expensive. Additionally, a voice communication routed over apacket-switched network may require less bandwidth than a voicecommunication placed over a circuit-switched network like a traditionaltelephone network. Packet-switched networks like the internet protocol(IP)-based Internet, Intranets, and Asynchronous Transfer Mode (ATM)networks handle bursty data more efficiently than circuit-switchednetworks because of statistical multiplexing of the packet streams.However, statistical variations of traffic intensity often lead tocongestion that results in excessive delays and loss of packets, therebysignificantly reducing the quality level of real-time voicecommunications.

One problem with sending packetized voice over packet-switched networksare the delays associated with channel reallocation. Packet delays abovea certain level (e.g., 100–300 mS) are generally found to be annoyingfor voice conversations. As a result, some networks supportingVoice-over-Packet (VoP) impose a maximum delay requirement of 100milliseconds (mS). One critical point in the design for such arequirement is the onset of a speech spurt (i.e., when a user starts tospeak after a pause or delay) when speech packets are initiallygenerated. Unlike conventional circuit-switched networks,packet-switched networks may not have a dedicated channel ready andavailable to immediately transfer the packet stream. In conventionalpacket-switched networks, a media access control device may be employedto reallocate an existing channel and grant access to the channel forthe voice packet stream. This channel allocation/reallocation processinvolves signaling between the various network elements and takes timethat can easily exceed an acceptable delay for voice communications aswell as the maximum delay requirement imposed on a packet-switchednetwork for voice communication. The channel allocation/reallocationtime may become significant especially when existing packet streams haveat least as great of a quality of service requirement which may preventreallocation of their channels. Packet-switched networks have employedpartial loading of the access medium (e.g., by reserving a channel) toalways allow some capacity for the initial speech onset to meet delayrequirements. However partial loading consumes bandwidth because thereserved capacity is unused when no speech packets are beingtransferred.

Thus there is a general need for an improved method and system for thecommunication of voice over a packet-switched network. There is also aneed for a method and system for communicating voice over apacket-switched network that more efficiently utilizes networkresources. There is also a need for a method and system forcommunicating voice over a packet-switched network that may increasenetwork capacity.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is pointed out with particularity in the appended claims.However, a more complete understanding of the present invention may bederived by referring to the detailed description when considered inconnection with the figures, wherein like reference numbers refer tosimilar items throughout the figures and:

FIG. 1 is a functional block diagram of a system for communicatingspeech packets in accordance with an embodiment of the presentinvention;

FIG. 2 illustrates the operation of the system of FIG. 1 in accordancewith an embodiment of the present invention;

FIG. 3 is a functional block diagram of user equipment in accordancewith another embodiment of the present invention; and

FIG. 4 is a flow chart of a voice over packet communication procedure inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION

The description set out herein illustrates the various embodiments ofthe invention and such description is not intended to be construed aslimiting in any manner. FIG. 1 is a functional block diagram of a systemfor communicating speech packets in accordance with an embodiment of thepresent invention. System 100 provides for the communication of speechpackets from sending user equipment 110 to receiving user equipment 150.Sending user equipment 110 may be any device that generates a stream ofpacketized speech and may be a wireline digital telephone, a computer,etc. Voice input element 112 digitizes a user's speech and suppliesdigitized speech samples to vocoder 114. Vocoder 114 may be a voiceencoder that encodes the speech samples in accordance with one or morespeech encoding techniques to generate a packet stream of speech packetsat a speech encoding rate. This packet stream may be sent over packetnetwork 120. Packet network 120 may be an internet protocol (IP) networkor any network suitable for the transfer of packetized communicationssuch as the internet, an intranet, or a local area network, and may eveninclude the public switched telephone network. Sending user equipment110 may add information to the speech packets such as source anddestination addressing for transfer of the speech packets throughnetwork 120. Sending user equipment 110 may also perform otheroperations on the speech packets including encryption. Packet network120 may transfer the speech packets from sending user equipment 110 tonetwork equipment 130 at the speech encoding rate without significantdelay. In other words, whenever vocoder 114 generates encoded speechpackets, the packet stream may be quickly transferred through packetnetwork 120. Other sending user equipment (not shown) may be coupledwith packet network 120 and may use packet network 120 forcommunications. In one alternate embodiment, sending user equipment 110may send the speech packets directly to network equipment 130 at thespeech encoding rate. In this embodiment, packet network 120 does notneed to be utilized.

Network equipment 130 interfaces between packet network 120 and accessnetwork 140. In the alternate embodiment, network equipment 130interfaces between sending user equipment 110 and access network 140.Access network 140 may be a packet-switched network comprised of acommunication medium that may provide for communication channels ofvarious bandwidths. The communication channels may be reserved ordedicated, or may be reallocated upon request. Examples of access mediasuitable for access network 140 include optical media, wireline media,the airwaves (i.e., wireless), and combinations thereof including, forexample, fiber optical networks, hybrid fiber coaxial (HFC) networks,and coaxial cable networks. When access network 140 is a wirelessnetwork, spread-spectrum multiplexing, frequency-division multiplexing,time-division multiplexing, and combinations thereof may be implementedby media access controller (MAC) 134 for communications through theairwaves. When access network 140 is a fiber optical network,wavelength-division multiplexing, frequency-division multiplexing, ortime-division multiplexing, for example, may be implemented by MAC 134for communicating through the access medium.

Upon receipt of the initial encoded speech packets from user equipment110, network equipment 130 buffers the packets in buffer 132 while MAC134 may reallocate (or allocate) a channel through access network 140 toreceiving user equipment 150. The encoded speech packets are bufferedfor a channel reallocation delay which may, for example, require up toone second or greater. Although a delay, for example, of greater than100 ms for voice communications may be considered unacceptable, adaptiveprocessing by receiving user equipment 150 compensates for this delay.During the channel reallocation delay, MAC 134 and user equipment 150may perform signaling in accordance with one or more protocols todetermine the communication parameters of the channel. Prior toreallocation, the channel may have been used for the communication ofother data streams. When an access channel is reallocated, MAC 134 sendsthe buffered speech packets through the channel at a packet transferrate that exceeds the speech encoding rate. The access channel, at leastinitially, has a greater bandwidth than required for transfer of thespeech packets at the speech encoding rate. In accordance with oneembodiment of the present invention, the rate at which the bufferedspeech packets are transferred through the access channel significantlyexceeds the speech encoding rate. The buffered packets may betransferred very quickly.

Reallocation as used herein, includes assigning or reassigning a portionof the spectrum through an access medium for a particular packet stream.In addition to signaling time, MAC 134 may, for example, have to waitfor packet streams having higher quality of service requirements (e.g.,less delay being allowed) before a channel is reallocated.

MAC 134 may also track a time stamp associated with each speech packetbeing buffered (e.g., using a real time transport protocol (RTP)) andmay notify receiving user equipment 150 of the time difference betweenthe buffered packets once the access channel is allocated. MAC 134 mayalso dump the oldest packets from the buffer when the time differenceexceeds a predetermined time.

User equipment MAC 152 receives the buffered speech packets sent by MAC134 at the packet transfer rate. User equipment MAC 152 may also receivethe time difference between the buffered packets from MAC 134. Vocoder154 may be a voice decoder that decodes speech packets. Vocoder 154 maydecode the speech packets at a rate which is a higher rate than thespeech encoding rate, and may decode the speech packets at the packettransfer rate. Vocoder 154 buffers the decoded speech packets in buffer156. The decoded speech packets substantially correspond with theinitial portion of speech packets generated by voice input element 112of sending user equipment 110 prior to voice encoding. User equipmentMAC 152 may also receive other packetized communications (such as dataor video for example) through network 140 and may provide these othercommunications to other elements (not shown) of user equipment 150. MAC152 may comprise a transceiver and/or demultiplexer depending on theparticular access medium for which equipment 150 is designed for.

Processing element 158 processes the decoded speech packets from buffer156 to generate speech signals representative of at least the initialportion of the speech packets. The generated speech signals have ashortened time period to compensate for the channel allocation delay. Inone embodiment, processing element 158 may process the decoded speechpackets from buffer 156 at a varying rate which may initially exceed thespeech encoding rate. The processing rate may be gradually decreased toapproximately the speech encoding rate. The varying rate at whichprocessing element processes the speech packets may be initiallyinversely proportional to the time difference between the bufferedpackets. Processing element 158 may use the time difference provided byMAC 134 to determine the rate of processing the buffered speech packets.Buffer 156 may act as a “leaky bucket” initially emptying the speechpackets at a higher rate and gradually tapering off to a lower ratewhich eventually approximates the input rate (e.g., the speech encodingrate) for subsequent portions of the speech segment.

Processing element 158 may use a rate matching process and may include adynamic time warping (DTW) process to dynamically time warp the speechpackets from buffer 156 from an initial rate to approximately the speechencoding rate while substantially preserving attributes of the originalspeech, such as pitch, for example. In a DTW process, portions of twopatterns may be compared and are brought into time alignment. The DTWprocess may shift portions of a speech waveform along the time axis tofind a match with another waveform. The splicing points of the shiftedportion may be smoothed with a filter.

To illustrate the operation of an embodiment of the present invention,consider a channel access delay of one second in which one second'sworth of encoded speech packets are buffered in buffer 132. Once achannel is allocated, the one second's worth of encoded speech packetsmay be transferred through network 140 to user equipment 150 at a highrate, decoded at a high rate and stored in buffer 154. Subsequent speechpackets (let's say three seconds worth, for example) may be sent throughthe channel at the speech encoding rate. Processing element 158 maygenerate voice signals over the next three seconds, for example, thatinclude the next three seconds worth of speech along with the initialone second's worth of buffered speech packets. Accordingly, in thisexample, four seconds worth of speech is provided to the user over aperiod of three seconds. A DTW process may, for example, preserve thepitch of the speech segment. From the recipient's perspective, thespeech may sound like the sender is speaking slightly more quickly.

Receiving user equipment 150 may be any user equipment or device forreceiving information from access network 140. Receiving user equipment150 may include communication devices such as wireline and wirelesstelephones, data terminals, portable computers, etc. For simplicity, notall functional elements of receiving user equipment 150 are illustratedin FIG. 1. One or more functional element of user equipment 150 may beimplemented in a digital signal processor (DSP).

FIG. 2 illustrates the operation of the system of FIG. 1 in accordancewith an embodiment of the present invention. Item 200 illustrates auser's speech activity which may be comprised of a series of speechsegments 202 separated by pauses 204. In reference to FIG. 1, encodedspeech packets may be generated by sending user equipment 110 for speechsegments 202 and may refrain from generating encoding speech packetsduring pauses 204. Item 210 illustrates the packet transport allocationthrough an access medium for the user's speech activity in accordancewith an embodiment of the present invention. A channel is allocated toother packet streams during time periods 212, while during time periods214, a channel is allocated for the communication of the speech packetsthat comprise speech segment 202. A channel allocation delay isillustrated between the start of one of speech segments 202 and thebeginning of time period 214, however little or no delay is illustratedfrom the completion of speech segments 202 and the reallocation of thechannel back to other streams during time periods 212. In other words,less time is required to send entire speech segment 202 through theaccess medium than the time it took to encode the speech segment.

Item 220 illustrates the effective throughput of the allocated channelthrough the access medium for communicating the speech packets inaccordance with an embodiment of the present invention. During time 222,there is no throughput because no channel for the speech segment hasbeen allocated. During time 224, the channel has been allocated and theinitial speech packets of the speech segment that have been buffered aretransferred at a high rate through the access medium. During time 226,the buffered packets may have all been transferred and packet transferrate through the access medium will approximate the speech encodingrate. Speech packets will continue at this rate until a pause occurs, atwhich time the channel is reallocated to other streams and the transferrate goes to zero during time 228.

Item 220 also illustrates channel allocation delay time 232 which isillustrated as being greater than channel allocation delay time 222. Asa result of a longer channel allocation delay, more speech packets arebuffered and may require a longer time 234 to transfer the packetsthrough the access medium and empty the buffer. Once the buffer isemptied, the packet transfer rate will again approach the speechencoding rate during time 236.

In one embodiment of the present invention, the rate at which thebuffered speech packets are transferred through the access medium may bea predetermined rate which exceeds the speech encoding rate, or may be amaximum rate for the channel. In an alternate embodiment of the presentinvention, the transfer rate of the buffered speech packets may bevariable (i.e., greater when there are more buffered speech packets totransfer).

Item 240 illustrates an instantaneous effective delay from therecipients perspective in accordance with an embodiment of the presentinvention. The delay grows during time 242 until the channel isallocated and the buffered speech packets are sent. Once a channel isreallocated and the initial packets are sent, the time delay decreasesand eventually levels off at the physical delay after time 244. In otherwords, the initial delay due to channel allocation is graduallyeliminated.

FIG. 3 is a functional block diagram of user equipment in accordancewith another embodiment of the present invention. User equipment 300 maybe similar to user equipment 100 (FIG. 1) but user equipment 300illustrates additional functional elements for the transmission ofspeech packets through an access medium as well as reception of speechpackets. User equipment 300 may operate as a two-way communicationdevice for communication of at least voice. Elements 352, 354, 356, 358and 359 correspond respectively with and provide similar functionalityas elements 152, 154, 156, 158 and 159 of user equipment 150 (FIG. 1).Elements 362, 364, 366 and 368 may provide similar functionality aselements 112, 114, 132 and 134 respectively of FIG. 1. Voice inputelement 362 and voice output element 359 may be combined in one element,and user equipment MAC 352, 368 may be one or more functional elements.

In addition to the functionality of user equipment 150 (FIG. 1), userequipment 300 buffers encoded speech packets until an access channel isgranted and MAC 368 transfers the buffered speech packet through accessnetwork 140 at a rate higher than the speech encoding rate. MAC 368,rather than reallocating a channel, may send a request to a MACassociated with access network 140 requesting allocation/reallocation ofa channel. In one embodiment, vocoders 356 and 364 may be implementedtogether to encode and decode speech packets. One or more functionalelement of user equipment 300 may be implemented in a DSP.

FIG. 4 is a flow chart of a voice over packet communication procedure inaccordance with an embodiment of the present invention. Procedure 400may be performed, for example, by the elements of system 100 (FIG. 1),or may be performed by user equipment 300 (FIG. 3), however otherequipment may also be suitable. Procedure 400 provides for thecommunication of speech packets through a packet-switched network andcompensates for channel allocation delays that may, for example, exceeddelays acceptable in voice conversation. In operation 402, speechsegments are encoded to generate encoded speech packets at a speechencoding rate. The encoded speech packets may be in the form of a packetstream and may traverse a packet network at substantially the speechencoding rate. In operation 404, an initial portion of the encodedspeech packets of the speech segment are buffered for a channelallocation delay. Upon the receipt of the initial encoded speechpackets, operation 406 requests allocation of a channel through anaccess medium. When the channel is allocated, operation 408 transfersthe buffered speech packets through the access medium at a rateexceeding the speech encoding rate.

In operation 410, the speech packets may be decoded at a rate greaterthan the speech encoding rate which may be at substantially the rate atwhich they were transferred through the access medium. The decodedpackets are buffered in operation 412 and operation 414 generates speechsignals over a shorted time to compensate for the channel allocationdelay time.

In one embodiment, operation 414 may process the decoded speech packetsfrom a buffer at a varying rate which initially exceeds the speechencoding rate. The rate may be gradually decreased to approximately thespeech encoding rate. The varying rate at which the buffered speechpackets are processed may be initially inversely proportional to thetime difference between the buffered packets. A buffer may be initiallyemptied at a higher rate and gradually tapering off to a lower ratewhich may approximate the input rate. Operation 414 may use a ratematching process and may include a dynamic time warping (DTW) process todynamically time warp the speech packets from a buffer, such as buffer156 (FIG. 1) from an initially higher rate to approximately the speechencoding rate while substantially preserving attributes of the originalspeech, such as pitch, for example.

Although the individual operations of procedure 400 are illustrated anddescribed as separate operations, it should be noted that one or more ofthe individual operations may be performed concurrently. Further,nothing necessarily requires that the operations be performed in theorder illustrated. Operation 402 may be performed, for example, bysending user equipment 110 (FIG. 1). Operations 404 through 408 may beperformed, for example, by network equipment 130 (FIG. 1). Operations410 through 414 may be performed, for example, by receiving userequipment 150 (FIG. 1). Operations 402 through 414 may also beperformed, for example, by user equipment 300 (FIG. 3).

Thus, a method and system for the communication of voice over apacket-switched network has been described. The system and method allowfor an increase in channel allocation time beyond a time delay that isacceptable for voice conversations. In one embodiment, a method andsystem for the communication of speech packets over a packet-switchednetwork is provided. The system and method allow for an increase inchannel reallocation time beyond a time delay that is acceptable forvoice conversations, and may provide for an increase in the capacity ofan access network. Initial speech packets may be buffered during achannel reallocation delay and sent through an access medium when achannel is granted. A media access controller may transmit the bufferedspeech packets through the access medium at a rate exceeding a speechencoding rate. At the receiving user equipment, the initial speechpackets received through the access medium may be decoded and buffered.The receiving user equipment may generate speech signals representativeof the initial speech packets and may have a shortened time period tocompensate for the channel reallocation delay. In one embodiment,decoded speech packets are processed using a rate matching processhaving a varying processing rate which initially exceeds the speechencoding rate and is gradually decreased to approximately the speechencoding rate. A dynamic time warping process may be used to implementrate matching and substantially preserve at least some attributes of theoriginal speech.

The foregoing description of the specific embodiments reveals thegeneral nature of the invention sufficiently that others can, byapplying current knowledge, readily modify and/or adapt it for variousapplications without departing from the generic concept, and thereforesuch adaptations and modifications are intended to be comprehendedwithin the meaning and range of equivalents of the disclosedembodiments. It is to be understood that the phraseology or terminologyemployed herein is for the purpose of description and not of limitation.Accordingly, the invention is intended to embrace all such alternatives,modifications, equivalents and variations as fall within the spirit andbroad scope of the appended claims.

1. A method of receiving packet-switched voice communications over anon-dedicated wireless communication channel comprising: receiving atleast an initial portion of speech packets at a transmission rateexceeding a speech encoding rate; decoding the speech packets at a rateexceeding the speech encoding rate; and generating speech signals fromthe decoded speech packets at a varying rate, the speech signals beingrepresentative of the initial portion of speech packets and having ashortened time period which at least in part compensates for a channelreallocation delay, wherein generating the speech signals at the varyingrate comprises: initially generating speech signals at a rate exceedingthe speech encoding rate; and decreasing the rate of generating thespeech signals to approximately the speech encoding rate.
 2. The methodof claim 1 wherein the varying rate initially exceeds the speechencoding rate and decreased gradually to approximately the speechencoding rate, and wherein the varying rate of generating speech signalsis initially greater than the speech encoding rate to compensate atleast in part for the channel reallocation delay.
 3. The method of claim1 further comprising buffering the decoded speech packets in a buffer,and wherein generating includes retrieving the decoded speech packetsfrom the buffer at the varying rate which initially exceeds the speechencoding rate, the varying rate being gradually decreased toapproximately the speech encoding rate.
 4. The method of claim 1 whereinprocessing generating includes processing the decoded speech packetswith a dynamic time warping process to generate speech signalsrepresentative of the initial portion of speech packets, the generatedspeech signals spanning a shorter time duration than the initial portionof speech packets and having substantially preserved pitch attributes ofthe initial portion of speech packets, and wherein the dynamic timewarping process compensates for an increased pitch resulting frominitially generating the speech signals at the rate exceeding the speechencoding rate.
 5. The method of claim 1 wherein the decoding isperformed at approximately the transmission rate.
 6. The method of claim1 wherein the initial portion of speech packets is buffered for thechannel reallocation delay until a wireless communication channelthrough a wireless access medium is granted, and wherein the initialportion of speech packets is sent in response to the channel beinggranted.
 7. The method of claim 6 wherein the wireless communicationchannel has a channel bandwidth that is approximately proportional to aninverse of the channel reallocation delay.
 8. The method of claim 2wherein the speech packets are received through a wireless accessmedium.
 9. The method of claim 1 wherein the speech signals correspondto actual audio signals that are to be heard by a person listening. 10.The method of claim 8 wherein the wireless access medium employs, atleast one of spread-spectrum multiplexing, frequency-divisionmultiplexing or time-division multiplexing.
 11. A wireless communicationdevice for communicating packet-switched voice communicationscomprising: a voice decoder to decode speech packets, at least aninitial portion of the speech packets being delayed by a channelreallocation delay; a buffer to store the decoded speech packets; and aprocessing element to generate speech signals from the decoded speechpackets at a varying rate initially exceeding a speech encoding rate tocompensate at least in part for the channel relocation delay, whereinthe speech signals are representative of the initial portion of thespeech packets and have, a shortened time period, wherein the processingelement decreases the rate of generating the speech signals toapproximately the speech encoding rate.
 12. The wireless communicationdevice of claim 11 wherein the communication device receives the initialportion of the speech packets at a rate exceeding the speech encodingrate, and the voice decoder decodes the initial portion of the speechpackets at a rate exceeding the speech encoding rate.
 13. The wirelesscommunication device of claim 11 wherein the initial portion of thespeech packets are buffered for a time approximating the channelreallocation delay prior to transmission through an access medium,wherein the channel reallocation delay includes time to grant a channelthrough the access medium.
 14. The communication device of claim 11wherein the processing element processes the decoded speech packets at aprocessing rate which initially exceeds the speech encoding rate andwhich is gradually decreased to approximately the speech encoding rate.15. The wireless communication device of claim 11 wherein the processingelement retrieves the decoded speech packets from the buffer at a ratewhich initially exceeds the speech encoding rate to initially generatethe speech signals at a rate exceeding the speech encoding rate, andwherein the processing element gradually decreases the rate ofgenerating the speech signals to approximately the speech encoding rate.16. The wireless communication device of claim 11 wherein processingelement processes the decoded speech packets with a dynamic time warpingprocess to generate speech signals representative of the initial portionof the speech packets, the speech signals spanning a shorter timeduration than the initial portion of the speech packets and havingsubstantially preserved pitch attributes of the initial portion of thespeech packets, and wherein the dynamic time warping process compensatesfor an increased pitch resulting from initially generating the speechsignals at the rate exceeding the speech encoding rate.
 17. The wirelesscommunication device of claim 11 wherein the communication devicereceives the initial portion of the speech packets at a transmissionrate and the voice decoder performs the decoding at approximately thetransmission rate.
 18. The wireless communication device of claim 11wherein the speech packets are received through a wireless communicationchannel that is granted through a wireless access medium, and whereinthe speech packets are buffered during the channel reallocation delayuntil the wireless communication channel is granted.
 19. The wirelesscommunication device of claim 18 wherein the wireless communicationchannel has a bandwidth that is is approximately proportional to aninverse of the channel reallocation delay.
 20. The wirelesscommunication device of claim 12 wherein the speech packets are receivedthrough a wireless access medium.
 21. The wireless communication deviceof claim 11 wherein the speech signals correspond to actual audiosignals that are to be heard by a person listening.
 22. The wirelesscommunication device of claim 20 wherein the wireless communicationmedium employs at least one of spread spectrum multiplexed, frequencydivision multiplexed or time division multiplexed communication signals.23. A system for communicating voice over a wireless communicationchannel comprising: a voice encoder to encode outbound speech packets ata speech encoding rate; an output buffer to store the encoded outboundspeech packets until a wireless communication channel is allocated forthe transmission of the encoded outbound speech packets; a voice decoderto decode speech packets received through the wireless communicationchannel, at least an initial portion of the speech packets being delayedby a channel reallocation delay; a decoder buffer to store the decodedspeech packets; and a processing element to generate speech signals fromthe decoded speech packets at a varying rate initially exceeding thespeech encoding rate to compensate for a channel allocation delay, andto decrease the varying rate to the speech encoding rate, wherein thespeech signals are representative of at least the initial portion of thespeech packets and have a shortened time period which compensates forthe channel allocation delay.
 24. The system of claim 23 wherein thespeech signals correspond to actual audio signals that are to be heardby a person listening.
 25. The system of claim 24 further comprising amedia access controller to receive inbound speech packets from awireless access medium, to transfer outbound speech packets to theaccess medium and to request allocation of the wireless communicationchannel for transmission of the outbound speech packets through thewireless access medium.
 26. The system of claim 25 wherein the mediaaccess controller sends the outbound speech packets through the wirelessaccess medium at a rate exceeding the speech encoding rate, and whereinthe processing element processes the decoded inbound speech packets togenerate the speech signals at a rate which initially exceeds the speechencoding rate and which is gradually decreased to approximately thespeech encoding rate.
 27. The system of claim 26 wherein processingelement processes the decoded inbound speech packets with a dynamic timewarping process to generate speech signals representative of the initialportion of the inbound speech packets, the speech signals spanning ashorter time duration than the initial portion of the inbound speechpackets and having substantially preserved pitch attributes of theinitial portion of the inbound speech packets, and wherein the dynamictime warping compensates for an increased pitch resulting from initiallygenerating the speech signals at the rate exceeding the speech encodingrate.
 28. The system of claim 23 wherein the voice decoder, the decoderbuffer, and the processing element are part of a wireless communicationdevice, and wherein the voice encoder and the output buffer are part ofa transmitting wireless communication device.